<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script type="text/javascript" src="../js/vue.js"></script>
    <title>Document</title>
</head>

<body>

    <div id="root">
        姓：<input type="text" v-model="firstname" /><br /><br />
        名：<input type="text" v-model="lastname" /><br /><br />
        全名：{{firstname}}-{{lastname}}
    </div>

    <script>
        new Vue({
            el: '#root',
            data() {
                return {
                    firstname: '张',
                    lastname: '三'
                }
            }
        })
    </script>

</body>

</html>